[[TITLE]]

Last fall I bought a yellow backpack because it looked like a lemon drop and I wanted more color in my life. I carried it out of the shop and suddenly… everyone owned a yellow backpack. On the bus: yellow backpack. In the coffee line: yellow backpack. In the coworking space: you guessed it. Had the city signed a pact to match me? Nope. My brain did.

That shock—that uncanny sense that something new has suddenly invaded your world—has a name: Frequency Illusion. It’s the bias where, after you notice something once, you start noticing it far more, and it feels like it’s everywhere.

We’re the MetalHatsCats team, and we’re building a Cognitive Biases app because we’ve learned the hard way: biases don’t need a lecture; they need a handle. Frequency Illusion has handles—habits, prompts, and tiny moves that keep you from building a cardboard city out of coincidences. Let’s get those into your hands.

What is Frequency Illusion – when something new suddenly appears everywhere and why it matters

You hear a new phrase at lunch—“dopamine detox”—and then the term pops up three times that afternoon. You test-drive an electric car, and suddenly they swarm your commute. You run a survey, spot three responses about “pricing confusion,” and the complaint seems to multiply as you read.

Frequency Illusion happens when two things kick in together:

• Selective attention: once your brain tags something as relevant, you notice it more often.
• Confirmation bias: noticing it more convinces you it’s happening more, reinforcing the tag.

Linguist Arnold Zwicky coined the term “frequency illusion” (Zwicky, 2006). He also wrote about the “recency illusion,” where new things feel newer and more widespread than they are (Zwicky, 2005). Psychologists have described the machinery underneath for decades: limited attention, top-down expectations, and availability heuristics (Kahneman, 1973; Tversky & Kahneman, 1973; Nickerson, 1998). Mix those, and you’ll swear the universe is trolling you with yellow backpacks.

Why it matters: Frequency Illusion changes how we allocate time, money, and trust. If you build products, invest, hire, diagnose, or learn, you can’t afford to chase shadows. Spotting the illusion protects you from fake waves—and helps you surf the real ones.

Here’s where it bites:

• Product decisions: You notice three users asking for dark mode, so you push it to the top of the roadmap, overlooking silent majority needs like reliability.
• Investing: Your feed mentions a stock twice; you start seeing it everywhere, mistake that for momentum, and buy high.
• Health: You read about a rare symptom, then your body “finds” it. Anxiety spikes. So does Google.
• Relationships: A partner says “fine” once in a clipped tone; now you hear it as withdrawal every time.
• Hiring: You read a success story about ex-athletes; candidates who played sports suddenly feel more qualified.

The illusion isn’t a bug. It’s a survival feature. It helps you lock onto patterns fast. But fast is not always accurate. The trick isn’t to turn it off. The trick is to measure before you multiply.

Examples

Let’s walk through a few vivid cases. Names are changed. The mistakes are not.

1) The sudden competitor

A founder hears three prospects say, “We’re also evaluating Northbear.” The name feels new. The words sting. Over the next two weeks, Slack pings and tweets about Northbear seem constant. She concludes Northbear is crushing the market and pivots marketing around them.

Post-mortem: A quick CRM query shows Northbear mentioned in 7% of deals—consistent with last quarter. What spiked wasn’t Northbear; it was awareness. Her team had shifted messaging toward enterprise buyers. Enterprise buyers had longer vendor lists, so they named Northbear more often. The real number didn’t move. Her attention did.

What helped: A weekly “competitor mentions” chart, filtered by segment. A rule: no strategic pivots unless a metric crosses a threshold for two consecutive weeks.

2) The health scare

Amir reads a thread about myocarditis. Later, he notices a skipped heartbeat climbing stairs. For the next month he “hears” a skip daily. Anxiety curls around each beat. He stops running.

A cardiologist orders a Holter monitor. Result: normal sinus rhythm, occasional benign ectopy—common and previously unnoticed. The “increase” was awareness and anxiety tightening the feedback loop.

What helped: A simple diary with binary checkboxes (“felt palpitations Y/N”), logged before reading health forums. A pattern emerged: more awareness on days spent doomscrolling. He reinstated running, monitored objectively, and scheduled a follow-up instead of a spiral.

3) The hiring myth

A manager interviews two ex-debate-team candidates who articulate well. She starts “seeing” great debate alums everywhere. She shifts her recruiting outreach toward debate clubs.

Quarterly review shows no performance difference, but a noticeable drop in team collaboration scores; the team skewed toward similar communication styles. What changed? Attention and later selection. Once she looked for debate background, more candidates with it matched because she tuned sourcing, not because the world grew more debate-heavy.

What helped: A structured evaluation rubric and a calibration session with anonymized profiles. She learned to record the trait she actually values (clear thinking under pressure) and test for it, not its proxy.

4) The streetlight and the purse

Elena’s purse gets snatched one block from a broken streetlight. She starts noticing dead lights all over. The city feels unsafe.

A light map shows 5% outages—unchanged year-over-year. What rose were her “hits.” Before the theft, burned-out bulbs were invisible; after, they were charged with meaning. Fear turned the light map in her head from grayscale to neon.

What helped: Reporting outages via the city app and walking with a friend the same route at day and dusk to reset her baseline. She also compared reported incidents month-to-month. Action restored proportion.

5) The trend mirage in analytics

A product team runs an A/B test for a sign-up flow. One afternoon, five users post on the forum about confusion. The PM declares the variant broken and halts the test.

Later, the stats show a small but significant improvement. The spike in forum posts? Funnel changes sent more traffic from a channel with chatty users. The PM’s feed filled with complaints because the forum cognition filter was on. When your ear is against a wall, the world sounds like a wall.

What helped: Pre-registering stopping rules. Don’t abort a test based on anecdote. Watch the primary metric and confidence, not the loudest comments.

6) The nomenclature plague

A dev learns about the word “idempotent” and then “sees” non-idempotent APIs everywhere. Code review slows because every endpoint looks suspicious.

A quick audit reveals only a handful of endpoints matter; the rest are benign. What changed? Attention and vocabulary. Once named, the problem seemed rampant. Names can function like glue for attention.

What helped: A scoped checklist for API stability, applied quarterly, not continuously. Language is a lens; checklists are the edge stops that keep you from over-zooming.

7) The relationship echo

Jess’s partner says “I’m fine” in a flat tone after a hard day. Jess notices the phrase twice in the next week, hears distance, and decides something is wrong. A fight follows.

They talk. Turns out “I’m fine” is a reflex filler, not code. Jess had tuned for it and started hearing it through a megaphone. Once tuned, neutral instances became charged. The pattern was in Jess’s attention, not in the partner’s feelings.

What helped: A simple script—“When you say ‘I’m fine,’ should I hear that as ‘I need space’ or ‘I’m okay’?”—and a shared check-in ritual after tense days.

These aren’t misperceptions in the sense of hallucinations. They’re misallocations of weight. That’s the beating heart of Frequency Illusion.

How to recognize and avoid it

You can’t stop your brain from flagging new things. You can stop yourself from turning flags into laws. Here’s how we do it as a team—and in our lives—without becoming robots.

1) Name the trigger

When you feel “it’s everywhere” swell in your chest, ask: What made this salient? A purchase? A fear? A conversation? New vocabulary acts like Velcro. So does social pain. Naming the first hook drains some magic from the illusion.

Practical move: Write one line in your notes—“I started noticing X after Y.” That’s your anchor.

2) Measure before multiplying

Anecdotes explode in memory. Numbers don’t. Before you declare a wave, grab a baseline:

• For work: Pull a quick count—mentions per week, tickets per 1,000 users, conversion rate variance by segment. Beware shifting denominators.
• For life: Keep a tiny tally in your phone. If you “see” electric cars everywhere, count for five days. If your tally doesn’t spike past random variance, let it go.

Practical move: Decide in advance what number would count as meaningful. “If competitor mentions double for two straight weeks, we respond.” Write it down.

3) Separate exposure from prevalence

Platforms tune what you see based on what you engage. That means a small change in your click behavior can make a giant change in your feed. Your window isn’t the world.

Practical move: Use two windows. Check a neutral source (public data, search trends, a newsletter with different priors). For health info, read a clinical summary, not just forums. For stock chatter, check average daily volume and fundamentals before believing the feed.

4) Use time to wash the lens

Frequency Illusion often fades as novelty decays. If the thing is truly increasing, it will keep increasing. If it’s an attention wave, it will smooth out.

Practical move: Delay big decisions by a fixed interval and log one more sample. “Sleep one night, then revisit.” Your brain will be less enchanted.

5) Disconfirm on purpose

Ask, “Where would this not show up?” If your competitor is “everywhere,” find a segment where they’re weak. If your symptom is “constant,” track one day when you were occupied and see if it drops.

Practical move: Flip your search terms. If you searched “X is dangerous,” search “X is safe.” If your feed is full of one narrative, read one competent counterargument.

6) Give your intuition a job, not a badge

Intuition is a detector, not a judge. Treat the “everywhere” feeling as a hypothesis generator. “It feels like more users want feature Y. Cool. Let’s test that.”

Practical move: Turn the feeling into an experiment—“We’ll sample 100 support tickets and code them blind for mentions of Y.” Make the test small and cheap; then act.

7) Use checklists

Checklists give you ballast. When novelty yanks you, they keep you from tipping.

Here’s a quick one to paste into your notes.

Mini-Checklist for “I’m seeing this everywhere”

• What changed in me? (purchase, fear, word, goal)
• What’s my last known baseline? (pull it)
• What denominator am I using? (total users, impressions, days)
• Did my exposure source change? (algorithm, group, habit)
• What would count as meaningful change? (threshold + time)
• What would disconfirm it? (one credible contrary indicator)
• What’s the smallest test I can run? (sample, log, A/B)
• When will I revisit? (timestamp)

If you follow that in five minutes, you’ll dodge most traps.

8) Watch for mood and identity

When a topic hits your identity or fear center, Frequency Illusion flares. New parents “see” dangers. New founders “see” funding news. Runners “see” shoe brands. That’s normal. It’s also when you’re easiest to mislead.

Practical move: Add a mood tag to your notes (“tired,” “anxious,” “excited”). Patterns will jump out. If you spot a bias that spikes with anxiety, slow down.

9) Team rituals beat individual willpower

In teams, build rituals that catch illusions:

• Before reacting to a “trend,” write a one-sentence operational definition. “A trend is X increasing by Y% for Z weeks.”
• Assign a “counterfactual buddy” in meetings—a rotating role that asks for the alternative story.
• Archive last quarter’s “it’s everywhere” claims and check them retroactively. Humble is cheaper than whiplash.

10) Keep a bias journal the lazy way

You don’t need a leather notebook, just a low-friction log. We built our Cognitive Biases app to be that—tap a bias, save a trigger, set a revisit reminder. Simple routines beat heroic memory.

Related or confusable ideas

Frequency Illusion sits in a messy family. Knowing the cousins helps you tell stories that fit the facts, not just your feelings.

• Confirmation bias: You favor evidence that supports your belief. Frequency Illusion feeds it: once you think X is everywhere, you see more X, which “confirms” it (Nickerson, 1998). But Frequency Illusion starts with attention. Confirmation bias is the loop that locks it in.

• Availability heuristic: You judge frequency by how easily examples come to mind (Tversky & Kahneman, 1973). Frequency Illusion makes examples flood your mind, so availability gets fooled.

• Selection bias: Your sampling process overrepresents certain cases. If you hang out in a Discord for indie hackers, “everybody” is shipping weeklies. That’s not the world; that’s your sample.

• Recency illusion: New usages feel ubiquitous because they’re new to you (Zwicky, 2005). You notice “because reasons” in blogs and think writers just started saying it. They didn’t; you just learned the phrase.

• Illusory correlation: You perceive a relationship where none exists. You see kids wearing hoodies and misbehaving and conclude hoodies cause misbehavior. Frequency Illusion can supply the raw material: you notice hoodies more after a complaint.

• Clustering illusion: You see clusters in random data and think they’re meaningful. You “notice” a rash of earthquakes, but seismic activity naturally clusters. If you begin noticing quake posts, your feed will cluster too.

• Priming: Exposure to a stimulus influences response to a later stimulus. If you hear “red,” you’re faster to see red things. That’s attention tuning again—the front door of Frequency Illusion.

• Baader-Meinhof phenomenon: A popular nickname for Frequency Illusion, coined on an online forum in the ’90s. Same animal, different collar.

The boundaries blur in practice. That’s fine. The fix—slow down, define, measure—works for all of them.

Wrap-up: A gentler way to see your world

It’s tempting to laugh at Frequency Illusion, to call it a brain glitch and move on. But I think of it as tenderness. Your mind pays attention to what might matter. You buy a lemon-drop backpack; your brain checks for your tribe. You read one scary symptom; your brain searches for danger. It’s trying to keep you safe, connected, and right.

You don’t need to shut that off. You need small rituals that keep the tenderness from turning into panic or arrogance. You need the habit of asking, “What changed in me? What changed in the world? How do I tell?” You need, sometimes, to count.

That’s why we’re building our Cognitive Biases app. Not to judge you, not to sterilize life, but to nudge you when the magic trick starts—tap the bias, set a check, make a tiny plan, and get your day back.

Notice more. Believe carefully. Act wisely. That’s the whole game.

FAQ

Q: Is Frequency Illusion the same as synchronicity? A: No. Synchronicity is the feeling that coincidences carry meaning. Frequency Illusion is the mechanism that makes coincidences feel common after you notice them. You can enjoy coincidences without assuming the universe is plotting.

Q: How long does Frequency Illusion last? A: Often a few days to a couple of weeks, depending on how charged the trigger is. It fades as novelty decays and as you collect disconfirming examples. If it sticks, check whether you’ve changed environments or incentives.

Q: Can marketers exploit Frequency Illusion? A: Yes. They seed salient cues—catchy phrases, distinctive colors, social proof—to make you notice their product and then keep noticing it. Guard against it by comparing baselines (market share, reviews, independent tests) and using waiting periods for purchases.

Q: How do I handle it when a team member insists “everyone” wants a feature? A: Ask for numbers and definitions. “How many mentions this week, in what segments, out of how many total conversations?” Set a threshold and timeframe together, then check a random sample. Treat their intuition as a hypothesis worth testing.

Q: What’s the fastest way to check myself in the moment? A: Say the sentence “It feels bigger because I’m tuned to it” out loud. Then do a two-minute count: log five examples and five counterexamples. If you can’t find counterexamples, expand your window—different time of day, different source.

Q: How does social media affect Frequency Illusion? A: Algorithms amplify it by feeding you more of what you engage with. A single click can redraw your world. Use multiple sources, private browsing for sensitive topics, and scheduled checks (not continuous scrolling).

Q: Can Frequency Illusion help me? A: Yes. Harness it to direct focus. If you want to learn design, tag design patterns; your brain will find them. If you want gratitude, write one specific thing each morning; you’ll “see” more good. It’s a spotlight—point it.

Q: Is it just a human thing? A: The mechanics—attention tuning, reinforcement—show up across cognitive systems. In machine learning, models overfit recent salient patterns; we combat that with regularization and held-out data. In humans, checklists and baselines are our regularization.

Q: I keep seeing warning signs at work. Am I paranoid or perceptive? A: Maybe both. Treat your sense as an early-warning system. Log objective events (missed deadlines, defect rates), set thresholds, and invite a colleague to co-audit. If the metrics move, act. If not, adjust your filter, not your courage.

Q: How do I talk about this without sounding dismissive? A: Validate the feeling, then shift to structure. “I see why it feels everywhere; I’m noticing it too. Let’s pull a baseline and define what ‘everywhere’ would look like in numbers.” Respect plus process keeps trust intact.

Checklist

A short, actionable list to keep pasted at the top of your notes. Use it when that “everywhere” feeling hits.

• State the trigger: “I started noticing X after Y.”
• Pull a baseline: last week/month numbers, or count for 3–5 days.
• Fix your denominator: what total are we dividing by?
• Check exposure shift: algorithm, group, time, channel changed?
• Set a threshold and timeframe: “Meaningful if +50% for 2 weeks.”
• Seek a counter-window: different source or segment.
• Run the smallest test: sample 50 items, A/B, diary for 5 days.
• Delay the big call: sleep on it; revisit on a set date.
• Write the decision rule: “If threshold met, do A; else do B.”
• Review your calls monthly; learn which signals fooled you.

If you want a nudge to make the checklist a reflex, we built our Cognitive Biases app to do exactly that—one tap to log a bias, one nudge to check it later, and enough structure to protect you from your most persuasive stories.